PostgreSQL: database statistics

The window presents a variety of statistics on the operation of cluster databasesPostgreSQL

Database stats

Presented pg_stat_database system view information

Database statistics

SELECT db.datid,
db.datname,
numbackends,
xact_commit,
xact_rollback,
blks_read,
blks_hit,
tup_returned,
tup_fetched,
tup_inserted,
tup_updated,
tup_deleted,
stats_reset,
slave.confl_tablespace,
slave.confl_lock,
slave.confl_snapshot,
slave.confl_bufferpin,
slave.confl_deadlock,
temp_files,
pg_size_pretty(temp_bytes),
deadlocks,
blk_read_time,
blk_write_time,
pg_size_pretty(pg_database_size(db.datid))
FROM pg_stat_database db
JOIN pg_stat_database_conflicts slave
ON db.datid=slave.datid
where db.datname=$$DBNAME

pg_config

Viewing the system table pg_config of a PostgreSQL database

select * from pg_config

pg_file_settings

Viewing the pg_file_settings system table PostgreSQL databases

select f.sourcefile,
f.name,
f.setting,
f.applied,
f.error
from pg_file_settings f

Language support

List of programming languages supported by PostgreSQL cluster

select l.lanname,
a.rolname,
l.lanispl,
l.lanpltrusted,
l.lanplcallfoid,
l.laninline,
l.lanvalidator
from pg_language l
left join pg_authid a
on l.lanowner=a.oid

Percentage before freezing

The page displays information about the performance of the PostgreSQL cluster's autovacuum processes. A percentage in the "Percentage before freezing" field close to zero indicates that the autovacuum does not have time to clean up the tables and there is a high probability of a situation in which it will be necessary to switch the database to single-user mode and perform vacuum full .

With a large number of tables with a low percentage, it is necessary to analyze the values of the auto vacuum parameters in order to change them to more aggressive values.

with rel_frozen as (
select c.oid::regclass as table_name,
(select e.nspname
from pg_catalog.pg_namespace e
where oid = c.relnamespace) as schema,
greatest(age(c.relfrozenxid), age(t.relfrozenxid)) as age,
greatest(age(c.relfrozenxid), age(t.relfrozenxid))*100./
(pow(2,31)-1) as perc_wrpa
from pg_class c
left join pg_class t on c.reltoastrelid = t.oid
where c.relkind in ('r','m')
)
select table_name::text "table",
schema,
100 - round(perc_wrpa::numeric,2) "froz"
from rel_frozen order by 3